Watch-balance staff



(N0 Modell) S. 85 M. BOTKOWSKY.

WATCH BALANCE STAFF.

No. 439,629. Patented Nov. 4, 1890.

W WM UNITED STATES PATENT OFFICE.

SAM. BOTKOIVSKY AND MORRIS BOTKOWSKY, OF CHICAGO, ILLINOIS.

WATCH-BALANCE STAFF.

SPECIFICATION forming part of Letters Patent No. 439,629, dated November 4, 1890.

Application filed October 21, 1389. Serial No. 327,745- (No model.)

To all whom it may concern:

Be it known that we, SAM. BOTKOVVSKY and MORRIS Bo'rKowsKY, citizens of Russia, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in BalanceJVheel Stafis for Watch es; and we do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

Our invention relates to improvements in the balance-wheel staff of watches. Its objectis to obviate the necessity of replacing a damaged staff by an entire new one by providing removable pivotal points, thus lessening the cost of repairs and removing the danger of throwing the wheel out of true balance.

In the accompanying drawings, which are i made on a scale many times larger than the working parts, Figure 1 shows a plan view of the balance-wheel; Fig. 2, a vertical cross-section through the line 1 1; Figs. 3 and 4, the two ends, respectively, of the staff; and Fig. 5, one of the removable pivotal pins.

Heretofore the staff A, upon which the balance-wheel B is pivoted, has been made of a single piece of steel, drawing to apoint at either end and tempered. Should the points become worn or damaged, it becomes necessary to replace the staff by a new one at great risk of shifting the center of gravity, or by taking the temper out of the points, new ones might be adjusted by drilling the ends of the staff, a difficult and uncertain operation.

Our improved staff is made in sections comprising a longitudinally-hollow body consisting of the two ends 0 D, screwed together, and the pivoted shaft E, lying within the body and of sufficient length to project from each end thereof. The shaft E may be formed of two separate pins 6 e, as shown, having the fiat heads e c,which lie adjacent to each other when in position; or the two heads may be united, so as to form a solid shaft having an annular flange midway of its length.

One of the body-pieces is provided with a chamber, as shown in the piece 0, to accommodate the flange formed by the heads of the pins. The'otherbody-piece, being screwed into this chamber, holds the shaft E firmly in place.

The pivotal shaft, whether made of a single piece or in two parts, will always be made of uniform size, so that a damaged shaft or pin may be at once replaced by another without possible danger of throwing the wheel out of balance.

\Ve claim- 1. As anew article of manufacture, a balance-wheel staif composed of a longitudinal hollow body made in sections screwed together, and a removable pivot-shaft secured within the hollow body of the staff, substantially as described.

2. In a balance-wheel staff, the combination of the hollow body A, composed of the parts 0 D, and the pivot-shaft E, consisting of the parts 6 e, as and for the purpose set forth.

3. The combination, with a balance-wheel,

of the staff consisting of the hollow body A,

composed of the parts 0 D, and the pivot-shaft E, secured within the body A, as described.

In testimony whereof we affix our signatures in presence of two Witnesses.

SAM. BOTKOWSKY. MORRIS BOTKOIVSKY.

Witnesses:

SPENCER WARD, FRANK G. WARD. 

